Amazingly enough, the Thermalright Ultra-90 heatsink is almost as powerful as the larger Ultra-120 heatsink. As you might have guessed the numbers trailing the 'Ultra' relate to fan size;
92mm or 120mm. Like the Ultra-120, the Thermalright Ultra-90 heatsink is built around three U-shaped heat pipes, a few dozen
widely spaced aluminum cooling fins and a copper base plate. The heatsink is
sold without a fan, the idea being it allows users to customize it with the fan of their choice. A good low
speed 92mm fan translates into quiet cooling, or a high speed 92mm fan would yield lower temperatures with some sacrifices to sound output.Over the next three pages of this Frostytech
review, we'll tell you if the Thermalright Ultra-90 is worth that $40 bucks or not... (Pssst. YES!!!)

FULL STORY @ FROSTYTECH(http://www.frostytech.com/articleview.cfm?articleID=2131)